The present invention relates in general to assemblies which control the flight path of a scale model airplane powered by a gasoline type powerful engine. In particular, the present invention relates to flight control about a pylon.
Previous attempts to control the flight of a model airplane about a pylon are shown in Freedman, U.S. Pat. No. 2,672,388 and Lohse, U.S. Pat. No. 2,299,582. These prior references utilize a single restraining line interconnecting the pylon and a wing tip of the model airplane. This is particularly disavantageous in that the single connection to the wing tip will act as a pivot or swivel should the model airplane encounter any turbulence as it flies about the pylon. These systems do not maintain the necessary control of the attitude of the model airplane and, upon encountering turbulence, a loss of control and subsequent crash will result.
Additionally, both prior patents disclose a rigid stop apparatus to prevent the model airplane from lifting the restraining line off the top of the pylon. The use of a rigid stop in both cases results in vertical oscillation of the model airplane once the restraining line connector contacts the stop. The vertical oscillations become progressively worse, constantly increasing in vertical amplitude until the model airplane crashes.
A further disadvantage of the Freedman apparatus is that it utilizes a pylon or support which is rectangular in cross-section and a ring which is larger in diameter than the diameter of the stop at the top of the pylon to connect the restraining line to the pylon. It has been found that in models which utilize the gasoline powered motor, the smallest available motor is so powerful that it could easily lift the pylon ring vertically up and over the stop and ultimately free the aircraft from the pylon, particularly with the erratic motion which would be produced by the four-sided pylon or support. The possible resultant condition of uncontrolled flight of the gasoline powered model airplane would be extremely hazardous to spectators and, even if no one were injured, the unrestrained model airplane could once again crash.